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// Copyright (c) the JPEG XL Project Authors. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
#include "lib/jxl/opsin_params.h"
#include <stdlib.h>
#include "lib/jxl/linalg.h"
namespace jxl {
#define INVERSE_OPSIN_FROM_SPEC 1
const float* GetOpsinAbsorbanceInverseMatrix() {
#if INVERSE_OPSIN_FROM_SPEC
return DefaultInverseOpsinAbsorbanceMatrix();
#else // INVERSE_OPSIN_FROM_SPEC
// Compute the inverse opsin matrix from the forward matrix. Less precise
// than taking the values from the specification, but must be used if the
// forward transform is changed and the spec will require updating.
static const float* const kInverse = [] {
static float inverse[9];
for (int i = 0; i < 9; i++) {
inverse[i] = kOpsinAbsorbanceMatrix[i];
}
Inv3x3Matrix(inverse);
return inverse;
}();
return kInverse;
#endif // INVERSE_OPSIN_FROM_SPEC
}
void InitSIMDInverseMatrix(const float* JXL_RESTRICT inverse,
float* JXL_RESTRICT simd_inverse,
float intensity_target) {
for (size_t i = 0; i < 9; ++i) {
simd_inverse[4 * i] = simd_inverse[4 * i + 1] = simd_inverse[4 * i + 2] =
simd_inverse[4 * i + 3] = inverse[i] * (255.0f / intensity_target);
}
}
} // namespace jxl
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